Electrically heated paint removing tool



Oct. 7, 1952 R. H. GREEN ELECTRICALLY HEATED PAINT REMOVING TOOL FiledDec. 27, 1949 mvn/rozz 1205527" H. GRfEN Patented Oct. 7, 1952ELECTRICALLY HEATED PAINT REMOVING TOOL Robert HrGreen, Cleveland, Ohio,assignor, by mesne assignments, to The Otto Konigslow Mfg. 00.,Cleveland, Ohio, a corporation of Ohio Application December 27, 1949,Serial No. 135,127

This invention relates to a tool for removing paint and the like, andmore particularly to an electrically heated hand tool for use inscraping paint and the like from wood or metal'surfaces.

It has been proposed to provide electrically heated paintrernoving toolsbut heretofore such tools have been bulky and relatively costly and havebeen difficult to use because of their awkward shapes and because thetools have been subject to clogging with the paint removed by the tools.

A general object of the present invention is the provision of anelectrically heated tool for removing paint and the like in which theabove mentioned difficulties have been obviated. Another object is theprovision of a compact, light and efficient tool for removing paint andthe like which can be manufactured at reasonable cost. Further objectsare the provision of a tool which can be used efficiently by unskilledworkers; the provision of a tool in which the danger of burning thepaint is minimized; the provision of a tool that is not subject toclogging or fouling by the paint; the provision'of a paint removing toolof such character which is light in weight:

4 Claims. (01. 219- -21) wardly away from the blade and the surface toand the provision of a tool which is shaped so that it naturally takesthe correct position for use when grasped by the users hand.

Further objects of the invention will become apparent from the followingdescription of a preferred form thereof, reference being made to theaccompanying drawings in which Figure 1 is a perspective showing a toolembodying the invention; Figure 2 is a side elevational view of the toolof Figure 1; Figure 3 is a transverse sectional View on an enlargedscale and with the thickness of certain of the parts exaggerated, takenalong the line 3-3 of Figure 2; and Figure 4 is a transverse sectiontaken along line l-d of Figure 2.

Briefly, I attain the above enumerated and other objects of my inventionby providing'a tool embodying a fiat electrically heated blade which isadapted to be disposed close to'but spaced from the surface of the workfrom which the paint or the like is to be removed whereby the paint orthe like is heated and softened by heat radiating from the adjacentsurface of the blade. The paint is scraped from the surface by asharpened scraping edge formed integrally with the blade and slantingdownwardly and forwardly toward the surface to be scraped at the frontof the blade. At the rear of the blade, the blade material is bent intoan integral hollow shank portion extending rearwardly and upbe scrapedand terminating in a handle supporting portion extending rearwardly andlying in a plane substantially parallel to but offset from the plane ofthe blade. A handle composed of wood or other material which is a poorconductor of heat is mounted on the handle supporting portion, thearrangement being such that when the handle is parallel to the surfaceof the work and the scraping edge in engagement with the work, theheated blade is parallel to the surface and out of contact with thesurface but closely spaced thereto. The blade is heated by an electricresistance heating element mounted on the upper side of the blade whichis away from the work and enclosed in a metallic housing member. Currentis supplied to the heating element through wires extending through thehandle and the hollow shank portion to the blade.

Referring now to the drawings, the flat, heated blade is indicated atit], the sharpened scraping edge at H, shank at [2 and the handlesupporting portion at [3. Preferably these parts are formed integrallyfrom a single piece of steel strip. The material is of suflicientthickness so that the blade will not be deflected to any substantialextent under the pressures exerted by the user; for example, stockhaving a thickness of about 1% inch is satisfactory.

The scraping edge H is provided simply by bending the forward end of theblade so that it extends downwardly and forwardly from the front of theblade at an angle of, for example, about and sharpening the downwardlybent portion to provide a scraping edge. The edge is disposed below theunder surface of the blade by a distance greater than the thickness ofthe usual paint film.

To provide a support for the handle M, the material of the blade iscontinued rearwardly and bent into the form of a tube to provide thetubular shank l2, the edges of the material abutting as at it. The shankextends rearwardly and upwardly away from the blade and the surface tobe scraped, which is indicated at S in Figure 2, at an acute angle; inthe drawing this angle is a little less than 30; preferably the angle iswithin the range of 20 to 45. The end of the shank portion is bent intosubstantial parallelism with the blade H) to provide the handlesupporting portion [3 and the handle M is slid over the portion I3 andsecured thereto as by the set screw [6. For thesake of appearance and inorder to eliminate sharp corners, the rear corners of the blade H] arecut olf as indicated 3 at [8 and I! so that the rear end of the blademerges into the shank as shown at 20 in Figures 1 and 2.

In order to heat the blade ID, an electric resistance heating element isdisposed on the upper side of the blade. This element consists of anappropriate number; of turns of .nichrome or other suitable resistanceWire 25 wound around a sheet 26 of mica or other appropriate insulatingmaterial, the turns of wire being spaced in conventional fashion toeliminate short .circuiting. The heating element is insulated from theblade by a sheet of mica or other insulating material 21 which isslightly wider and longer'zthan the heating element itself. Above 'the'heating element there is a similar layer of mica or other suitableinsulatin material 28. 'Above .this is a thin reflective metallic sheet29 provided to reflect downwardly the heat generated by the heatingelement, and in engagement with the upper side. ofthe sheet 29 there isprovided a .thin layer30 of asbestos or other-fireproof heatinsulatingmaterial.

Inorder to retain the heating element and'the several layers associatedtherewith in place on the blade andtoprotect the heating element and thelayers, the housing member,3l is preferably employed. Member 3| is ahollow stamping composed of lightgauge-steel and having a flange32-Which is spot weldedto the blade Ill atseveral pointsasindicateddiagrammatically to 33. The depth-of thehousing withrespect tothe-thicknessof the several layers with-in it is preferably suchthat thelayers are slightly compressed between the housing and'the blade, thusretaining the parts-in position and improving the heat transfer to theblade. The housing 3i also has an upstruckconical-portion .34, the-rearend of which overlies the .end' of the shank l2 and'provides within it apassagewayfor the leads (not shown) of the resistance .wires25.

The leads are preferably insulatedwith fiber glass or other heatresistant insulation and extend into the shank i2 where'they are splicedto the conductors 31 and 38 of the cord or cable 39 which extendsthrough a central bore in the handle M; cord'39 is provided-at its endwith a conventional plug 40 so that thetool can beconnected to anyordinary outlet.

vIn use the tool :is positioned with respect to'the surface to bescraped as shown in Figure 2. It will be noted that when the. handle I4is arallel to thesurfaces, then the blade It is also parallel and whentheedge I I is in contact with the surface S the blade ID is disposedclose to but out of contact with-the uppersurface of the paint film P.Thisis'the'position'the toolnaturally takes when the handle isgraspedbythe users hand. When the. heated blade is so disposed, thepaintfllm P israpidly heated and softened as diagrammatically indicatedat P. Thenthe tool isiliftedfrom the work, moved rearwardly a shortdistance, the edge I I appliedto the softened portion of thefilmwiththeblade- H3 parallel to the surface and the tool pushed forward topeel the softened'paint off of the surfaces. The softened paint film isdeflected away from the heated surface of the blade [0 by'the edge H asindicated at -P".. While thescraping operation'isgoing onpthe .heatradiatedfrom blade. I0 softensthe next adjacent area of thepaint,-thetool is again lifted from engagement with the surface and moved:rearwardly .as; before, the-forward scrapingroperation is repeated,-and so on. The; path ofthettool is generally as shown by the arrows inFigure 2; the center of the orbit of the tool is moved rearwardly aftereach forward scraping movement so that the tool and the softening actionof the heated blade l0 move rearwardly and on each forward scrapingmovement the scraping edge acts on newly softened paint.

Inasmuch as-the scraping edge is at the extreme forward portion of thetoolgthetool can be used in close quarters without difliculty. The

scraping edge supports the heated blade out of contact with the softenedpaint, and the softened paintis deflected away from the heated blade bythe scraping edge. The paint does not come into contact with the. heatedblade; danger of fire is thus eliminated; the blade is maintained inclean condition-and ordinarily the operation is carried out without theproduction of smoke or noxious fumes from the paint. The construction issimple and the device is light so that it can be used without unduefatigue. The disposition of the handle with relation to the blade is.suchthat when the device is inusethe blade is naturally positionedcorrectly with respect to the surface to be scraped. The heating elementis efficient and does not become fouled with melted orburning paint. Forthese reasons the power consumed by the device is small; heatingelements of from to 250 watts have operatedsatisfactorily in tools inwhich the, heated portion of. the blade .18 measures approximately .2 3inches. The tool functions rapidly and economically to remove paintandthe like, and because of .its simple construction,.it can bemanufactured .at reasonable cost.

vVariouschanges and modifications inthe preferred form of the inventiondescribed herein will be apparent to those skilledin the art. ..It istherefore to be understood thatmy patent is not limited by the foregoingdescriptionand thatthe scope of the invention .is defined by theappended claims.

I claim:

1. An electrically heated paint removing tool comprising a flat steelblade having at the forward end thereof an integrally formed downwardlyand forwardly extending scraping edge terminating below the plane. ofthe lower surface of said blade, athin flat electric resistance heatingelement mounted on. the uppersurface of said blade, a layer .of heatreflectingmaterial disposed abovesaid element, a layerof heat.insulating material disposed above said layer of heat reflectingmaterial, .a housing enclosing andcompressing said heating element andsaid layers,.said housing comprising .a hollow steel stamping having -aperipheral flange welded .tothe upper surface of said b1ade,.a hollowshank formed integrally with said blade and extending upwardly andrearwardly from the rear end ofsaid blade and terminating in a handlesupporting portion extending rearwardly and parallel to and offset vfromsaid blade,. said housing having a conicalraised portion overlying theend of said, shank :at the Juncture of-saidshank and said blade, ahandle composed of heat insulating material mounted on said handlesupporting portion, and conductors extending within, said *handle, saidhandle supporting portion, said hollowshank and said conical raisedportion-for, supplyingelectricity. to said heating element.

2. Anelectricallyheated paint removing tool comprising a 'flat bladehaving at theforward end thereofan, integrally formed downwardly-andforwardly extending scraping edge terminating below the plane ofv the.lower surface-ofsaid blade,

a thin flat electric resistance heating element mounted on the uppersurface of said blade, a layer of heat reflecting material disposedabove said element, a layer of heat insulating material disposed abovesaid layer of heat reflecting material, a housing enclosing said heatingelement and said layers, said housing comprising a hollow stampinghaving a peripheral flange welded to the upper surface of said blade, ahollow shank formed integrally with said blade and extending from therear end of said blade and terminating in a handle supporting portion,said housing having a conical raised portion overlying the end of saidshank at the juncture of said shank and said blade, a handle composed ofheat insulating material mounted on said handle supporting portion andlying parallel to and offset from said blade, and conductors extendingwithin said handle, said handle supporting portion, said hollow shankand said conical raised portion for supplying electricity to saidheating element.

3. An electrically heated paint removing tool comprising an imperf-orateflat blade having at the forward end thereof an integrally formeddownwardly and forwardly extending scraping edge terminating below theplane of the lower surface of said blade and below the adjacent lateraledges thereof, a thin flat electric resistance heating element mountedon the upper surface of said blade, a layer of heat insulating materialdisposed above said heating element, a housing enclosing said heatingelement and said layer, said housing comprising a hollow stamping havinga peripheral flange secured to said blade, a

hollow shank formed integrally with said blade and extending upwardlyand rearwardly from the rear end of said blade and terminating in arearwardly extending handle supporting portion, said housing having aconical raised portion overlying the end of said shank at the junctureof said shank and said blade, a handle composed of heat insulatingmaterial mounted on said handle supporting portion and extendingrearwardly therefrom and being ofiset from said blade, and

conductors extending within said handle, said handle supporting portion,said hollow shank and said conical raised portion for supplyingelectricity to said heating element.

4. An electrically heated paint removing tool comprising a fiat bladehaving at the forward end thereof an integrally formed downwardly andforwardly extending scraping edge adapted to scrape upon forwardmovement of the tool, said scraping edge terminating below the plane ofthe adjacent lower surface of said blade and below the adjacent lateraledges thereof by a distance greater than the thickness of the usualpaint coating, a thin fiat electric resistance heating element mountedon said blade and extending over the major portion of the area thereof,a housing enclosing said heating element, said housing comprising ahollow stamping having the peripheral edges thereof secured to saidblade, a hollow shank formed integrally with said blade and extendingupwardly and rearwardly from the rear end of said blade and terminatingin a rearwardly extending handle supporting portion, said housing havinga portion overlying the end of said shank at the juncture of said shankand said blade, a handle composed of heat insulating material mounted onsaid handle supporting portion and extending rearwardly therefrom andbeing offset upwardly from said blade, and conductors extending withinsaid hollow shank and said portion of said housing for supplyingelectricity to said heating element.

ROBERT E. GREEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED I STATES PATENTS Number Name Date 1,809,718 McNeil June 9, 19312,109,022 Daniels Feb. 22, 1938 2,256,648 Preisser Sept. 23, 1941.2,263,222 Morris Nov. 18, 1941 2,315,121 King -1 Mar. 30, 1943 2,497,535Carlino Feb. 14, 1950 FOREIGN PATENTS Number Country Date 124,805Switzerland Mar. 1, 1928 225,016 Switzerland June 1, 1943 322,418 GreatBritain Dec. 5, 1929 540,510 Great Britain ,1 Oct. 20, 1941

